Now fund-raisers are demanding to know why the thieves cannot be caught and how people managed to steal the toys in the first place.

A police spokesman said: "Detectives have examined several hours of CCTV footage from within the hospital, and externally. "They have also spoken to members of staff who were on duty on the ward during the time of the theft.

"However, no lines of inquiry were identified and there were also no forensic opportunities. As such, unless further information comes to light, all lines of inquiry have been exhausted."

The theft from the 'Adolescent Room' – one of two playrooms at the hospital – was discovered on December 17.

The thieves also damaged furniture and tore down decorations made by children.

It is still not clear how the thieves got in to the Children's Centre, which is a locked-down area, as there was no evidence of forced entry.

University Hospital charity manager Lynette Barlow said: "Stealing from sick children at Christmas time is deplorable and we hope this never happens again." Some of the presents had been donated by Stoke City players during a visit.

Osman Kose, aged 33, of Clayton, whose 16-month-old daughter Rumeysa was visited by the Stoke stars as she recovers from cancer, said: "You would think the thieves would have been caught on CCTV."

Fund-raiser Craig Longson, aged 38, of Stoke, who collected gifts following the thefts, said: "For people just to be able to waltz in off the street and steal and destroy toys and decorations in a hospital is just bizarre. There are obviously security issues which need to be addressed. "

Fellow fund-raiser Stan Bridge, aged 51, of Hanley, added: "It's a real shame the police haven't caught the people responsible. The way people came together after the theft was amazing, so at least some good came of it."

If you know the thieves call police on 101, quoting incident number 116 of December 17.